An estimated 300 million people worldwide suffer from asthma. Asthma is a chronic disease of the airways of the lungs, notably airway inflammation and constriction. The exact cause of asthma is still unknown, but there are several known triggers including allergies, environmental pollutants and dietary intake. Several recent studies now suggest a vegetarian diet consisting of high consumption of fruits, vegetables, grains and nuts can greatly improve asthmatic symptoms while the increasingly prevalent fast food diet of Western countries can exacerbate asthma.
What is it about fast food that increases asthma symptoms? The exact cause is unknown, but fast food contains known asthma triggers such as the high content of omega-6 fat. Preservatives of highly processed food are also known triggers. In particular, sulfite additives, such as sodium bisulfite, potassium bisulfite, sodium metabisulfite, potassium metabisulfite, and sodium sulfite, are commonly used in fast food preparation.
When put on a vegan diet, asthmatics note significant clinical improvement in markers such as vital capacity, FEV1, and physical working capacity. In one study, an incredible ninety-two percent of patients had significant improvement on their vegan diet which excluded all meat, fish, eggs, and dairy products. (J Asthma. 1985;22:45–55). In another study, children who got the most calories from cereal and rice and the most protein from cereals, nuts, starch, and vegetables were the ones most protected against wheezing, according to the International Study of Asthma and Allergies in Childhood (ISAAC), an Auckland, New Zealand-based group, which has been studying the diets of more than 700,000 children ages 6, 7, 13, and 14 from 53 countries, including the U.S.
The reason why vegetarian diets help to improve asthma is most likely the high content of antioxidants found in fruits, vegetables and nuts. Vitamins C and E , beta carotene and selenium are thought to provide important defense. These antioxidants may help reduce lung swelling and irritation (inflammation) caused by cell-damaging chemicals known as free radicals. Vitamin C is found in peppers, berries, citrus fruit, kiwis, and green vegetables from the cabbage family. These green, yellow and orange fruits and vegetables are high in carotenoids. Wheat germ oil, nuts and seeds, and grains are high in vitamin E. Vegetarian sources of selenium include wheat germ and brewer’s yeast.